Soybean variety 91B42

ABSTRACT

A soybean variety designated 91B42, the plants and seeds of soybean variety 91B42, methods for producing a soybean plant produced by crossing the variety 91B42 with itself or with another soybean plant, and hybrid soybean seeds and plants produced by crossing the variety 91B42 with another soybean variety or plant, and the creation of variants by mutagenesis or transformation of variety 91B42. This invention also relates to methods for producing other soybean varieties or breeding varieties derived from soybean variety 91B42 and to soybean varieties or breeding varieties produced by those methods.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/271,231, now U.S. Pat. No. 6,855,874, filed on Oct. 15, 2002 which isa non-provisional of U.S. Patent Application Ser. No. 60/352,800 filedJan. 29, 2002, the contents of which are hereby incorporated byreference in their entirety.

FIELD OF INVENTION

This invention is in the field of soybean breeding, specificallyrelating to a soybean variety designated 91B42.

BACKGROUND OF INVENTION

The present invention relates to a new and distinctive soybean variety,designated 91B42 which has been the result of years of careful breedingand selection as part of a soybean breeding program. There are numeroussteps in the development of any novel, desirable plant germplasm. Plantbreeding begins with the analysis and definition of problems andweaknesses of the current germplasm, the establishment of program goals,and the definition of specific breeding objectives. The next step isselection of germplasm that possess the traits to meet the programgoals. The goal is to combine in a single variety an improvedcombination of desirable traits from the parental germplasm. Theseimportant traits may include higher seed yield, resistance to diseasesand insects, tolerance to drought and heat, and better agronomicqualities.

Field crops are bred through techniques that take advantage of theplant's method of pollination. A plant is self-pollinated if pollen fromone flower is transferred to the same or another flower of the sameplant. A plant is sib-pollinated when individuals within the same familyor variety are used for pollination. A plant is cross-pollinated if thepollen comes from a flower on a different plant from a different familyor variety. The terms “cross-pollination” and “out-cross” as used hereindo not include self-pollination or sib-pollination. Soybean plants(Glycine max), are recognized to be naturally self-pollinated plantswhich, while capable of undergoing cross-pollination, rarely do so innature. Insects are reported by some researchers to carry pollen fromone soybean plant to another and it generally is estimated that lessthan one percent of soybean seed formed in an open planting can betraced to cross-pollination, i.e. less than one percent of soybean seedformed in an open planting is capable of producing F₁ hybrid soybeanplants, See Jaycox, “Ecological Relationships between Honey Bees andSoybeans,” appearing in the American Bee Journal Vol. 110(8): 306-307(August 1970). Thus intervention for control of pollination is criticalto establishment of superior varieties.

A cross between two different homozygous varieties produces a uniformpopulation of hybrid plants that may be heterozygous for many gene loci.A cross of two plants that differ at a number of gene loci will producea population of hybrid plants that differ genetically and will not beuniform. Regardless of parentage, plants that have been self-pollinatedand selected for type for many generations become homozygous at almostall gene loci and produce a uniform population of true breeding progeny.

Soybeans, (Glycine max), can be bred by both self-pollination andcross-pollination techniques. Choice of breeding or selection methodsdepends on the mode of plant reproduction, the heritability of thetrait(s) being improved, and the type of variety used commercially(e.g., F₁ hybrid variety, pureline variety, etc.). For highly heritabletraits, a choice of superior individual plants evaluated at a singlelocation will be effective, whereas for traits with low heritability,selection should be based on mean values obtained from replicatedevaluations of families of related plants. Popular selection methodscommonly include pedigree selection, modified pedigree selection, massselection, and recurrent selection.

Soybean plant breeding programs combine the genetic backgrounds from twoor more lines, varieties or various other germplasm sources intobreeding populations from which new lines or varieties are developed byselfing and selection of desired phenotypes. Plant breeding and variety,line or hybrid development, as practiced in a soybean plant breedingprogram developing significant genetic advancement, are expensive andtime consuming processes.

Mutation breeding is one of the many methods of introducing new traitsinto soybean varieties. Mutations that occur spontaneously or areartificially induced can be useful sources of variability for a plantbreeder. The goal of artificial mutagenesis is to increase the rate ofmutation for a desired characteristic. Mutation rates can be increasedby many different means including temperature, long-term seed storage,tissue culture conditions, radiation; such as X-rays, Gamma rays (e.g.cobalt 60 or cesium 137), neutrons, (product of nuclear fission byuranium 235 in an atomic reactor), Beta radiation (emitted fromradioisotopes such as phosphorus 32 or carbon 14), or ultravioletradiation (preferably from 2500 to 2900 nm), or chemical mutagens (suchas base analogues (5-bromo-uracil), related compounds (8-ethoxycaffeine), antibiotics (streptonigrin), alkylating agents (sulfurmustards, nitrogen mustards, epoxides, ethylenamines, sulfates,sulfonates, sulfones, lactones), azide, hydroxylamine, nitrous acid, oracridines. Once a desired trait is observed through mutagenesis thetrait may then be incorporated into existing germplasm by traditionalbreeding techniques. Details of mutation breeding can be found in“Principals of Cultivar Development” Fehr, 1993 Macmillan PublishingCompany the disclosure of which is incorporated herein by reference.

Choice of breeding or selection methods depends on the mode of plantreproduction, the heritability of the trait(s) being improved, and thetype of variety used commercially (e.g., F₁ hybrid variety, purelinevariety, etc.). For highly heritable traits, a choice of superiorindividual plants evaluated at a single location will be effective,whereas for traits with low heritability, selection should be based onmean values obtained from replicated evaluations of families of relatedplants. Popular selection methods commonly include pedigree selection,modified pedigree selection, mass selection, and recurrent selection.

The complexity of inheritance influences choice of the breeding method.In general breeding starts with the crossing of two genotypes, each ofwhich may have one or more desirable characteristics that is lacking inthe other or which complements the other. If the two original parents donot provide all the desired characteristics, other sources can beincluded by making more crosses. In each successive filial generation,superior plants are selected and self-pollinated which increases thehomozygosity of the varieties. Typically in a breeding program five ormore successive filial generations of selection and selfing arepracticed: F₁→F₂; F₂→F₃; F₃→F₄; F₄→F₅, etc. After a sufficient amount ofinbreeding, successive filial generation will serve to increase seed ofthe developed variety. Preferably, a developed variety compriseshomozygous allele at about 95% or more of its loci.

Pedigree breeding is commonly used for the improvement ofself-pollinating crops. Two parents that possess favorable,complementary traits are crossed to produce an F₁. An F₂ population isproduced by selfing one or several F₁'s or by intercrossing two F₁'s(sib mating). Selection of the best individuals may begin in the F₂population; then, beginning in the F₃, the best individuals in thesuccessive filial generations are selected. Replicated testing offamilies can begin in the F₄ generation to improve the effectiveness ofselection for traits with low heritability. At an advanced stage ofinbreeding (i.e., F₆ and F₇), the best varieties or mixtures ofphenotypically similar varieties are tested for potential release as newvarieties.

Backcross breeding has been used to transfer genes for simply inherited,highly heritable traits from a donor parent into a desirable homozygousvariety that is utilized as the recurrent parent. The source of thetraits to be transferred is called the donor parent. After the initialcross, individuals possessing the desired trait or traits of the donorparent are selected and then repeatedly crossed (backcrossed) with therecurrent parent. The resulting plant is expected to have the attributesof the recurrent parent (e.g., variety) plus the desirable trait ortraits transferred from the donor parent. This approach has been usedextensively for breeding disease resistant varieties.

Each soybean breeding program should include a periodic, objectiveevaluation of the efficiency of the breeding procedure. Evaluationcriteria vary depending on the goal and objectives, but should includegain from selection per year based on comparisons to an appropriatestandard, overall value of the advanced breeding varieties, and numberof successful varieties produced per unit of input (e.g., per year, perdollar expended, etc.).

Various recurrent selection techniques are used to improvequantitatively inherited traits controlled by numerous genes. The use ofrecurrent selection in self-pollinating crops depends on the ease ofpollination and the number of hybrid offspring from each successfulcross.

Mass selection and recurrent selection can be used to improvepopulations of either self- or cross-pollinated crops. A geneticallyvariable population of heterozygous individuals is either identified orcreated by intercrossing several different parents. The best plants areselected based on individual superiority, outstanding progeny, orexcellent combining ability. The selected plants are intercrossed toproduce a new population in which further cycles of selection arecontinued.

The single-seed descent procedure in the strict sense refers to plantinga segregating population, harvesting a sample of one seed per plant, andusing the one-seed sample to plant the next generation. When thepopulation has been advanced from the F₂ to the desired level ofinbreeding, the plants from which varieties are derived will each traceto different F₂ individuals. The number of plants in a populationdeclines each generation due to failure of some seeds to germinate orsome plants to produce at least one seed. As a result, not all of the F₂plants originally sampled in the population will be represented by aprogeny when generation advance is completed.

In a multiple-seed procedure, soybean breeders commonly harvest one ormore pods from each plant in a population and thresh them together toform a bulk. Part of the bulk is used to plant the next generation andpart is put in reserve. The procedure has been referred to as modifiedsingle-seed descent or the pod-bulk technique.

The multiple-seed procedure has been used to save labor at harvest. Itis considerably faster to thresh pods with a machine than to remove oneseed from each by hand for the single-seed procedure. The multiple-seedprocedure also makes it possible to plant the same number of seeds of apopulation each generation of inbreeding. Enough seeds are harvested tomake up for those plants that did not germinate or produce seed.

Molecular markers which includes markers identified through the use oftechniques such as such Isozyme Electrophoresis, Restriction FragmentLength Polymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs(RAPDs), Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNAAmplification Fingerprinting (DAF), Sequence Characterized AmplifiedRegions (SCARs), Amplified Fragment Length Polymorphisms (AFLPs), SimpleSequence Repeats (SSRs), and Single Nucleotide Polymorphisms (SNPs) maybe used in plant breeding methods. One use of molecular markers isQuantitative Trait Loci (QTL) mapping. QTL mapping is the use ofmarkers, which are known to be closely linked to alleles that havemeasurable effects on a quantitative trait. Selection in the breedingprocess is based upon the accumulation of markers linked to the positiveeffecting alleles and/or the elimination of the markers linked to thenegative effecting alleles from the plant's genome.

Molecular markers can also be used during the breeding process for theselection of qualitative traits. For example, markers closely linked toalleles or markers containing sequences within the actual alleles ofinterest can be used to select plants that contain the alleles ofinterest during a backcrossing breeding program. For example, molecularmarkers are often used in soybean breeding for selection of the trait ofresistance to soybean cyst nematode, See, U.S. Pat. No. 6,162,967. Themarkers can also be used to select for the genome of the recurrentparent and against the markers of the donor parent. Using this procedurecan minimize the amount of genome from the donor parent that remains inthe selected plants. It can also be used to reduce the number of crossesback to the recurrent parent needed in a backcrossing program. The useof molecular markers in the selection process is often called GeneticMarker Enhanced Selection. Molecular markers may also be used toidentify and exclude certain sources of germplasm as parental varietiesor ancestors of a plant by providing a means of tracking geneticprofiles through crosses as discussed more fully hereinafter.

The production of double haploids can also be used for the developmentof homozygous varieties in the breeding program. Double haploids areproduced by the doubling of a set of chromosomes (1N) from aheterozygous plant to produce a completely homozygous individual. Forexample, See Wan et al., “Efficient Production of Doubled Haploid PlantsThrough Colchicine Treatment of Anther-Derived Maize callus” Theoreticaland Applied genetics, 77:889-892, 1989. This can be advantageous becausethe process omits the generations of selfing needed to obtain ahomozygous plant from a heterozygous source.

Descriptions of other breeding methods that are commonly used fordifferent traits and crops can be found in one of several referencebooks (e.g., Allard, Principles of Plant Breeding, 1960; Simmonds,Principles of Crop Improvement, 1979; Sneep et al., 1979; Fehr,“Breeding Methods for Cultivar Development”, Chapter 7, SoybeanImprovement, Production and Uses, 2^(nd) ed., Wilcox editor, 1987).

Promising advanced breeding varieties are thoroughly tested and comparedto appropriate standards in environments representative of thecommercial target area(s). The best varieties are candidates for newcommercial varieties; those still deficient in a few traits may be usedas parents to produce new populations for further selection.

A most difficult task is the identification of individuals that aregenetically superior, because for most traits the true genotypic valueis masked by other confounding plant traits or environmental factors.One method of identifying a superior plant is to observe its performancerelative to other experimental plants and to a widely grown standardvariety. Generally a single observation is inconclusive, so replicatedobservations are required to provide a better estimate of its geneticworth.

Thus, even if the entire genotypes of the parents of the breeding crosswere characterized and a desired genotype known, only a few if anyindividuals having the desired genotype may be found in a largesegregating F₂ population. It would be very unlikely that a breeder ofordinary skill in the art would be able to recreate the same varietytwice from the very same original parents as the breeder is unable todirect how the genomes combine or how they will interact with theenvironmental conditions. This unpredictability results in theexpenditure of large amounts of research resources in the development ofa superior new soybean variety. Breeders use various methods to helpdetermine which plants should be selected from the segregatingpopulations and ultimately which varieties will be used forcommercialization. In addition to the knowledge of the germplasm andother skills the breeder uses, a part of the selection process isdependent on experimental design coupled with the use of statisticalanalysis. Experimental design and statistical analysis are used to helpdetermine which plants, which family of plants, and finally whichvarieties are significantly better or different for one or more traitsof interest. Experimental design methods are used to assess error sothat differences between two varieties can be more accuratelydetermined. Statistical analysis includes the calculation of meanvalues, determination of the statistical significance of the sources ofvariation, and the calculation of the appropriate variance components.Either a five or a one percent significance levels is customarily usedto determine whether a difference that occurs for a given trait is realor due to the environment or experimental error.

One of ordinary skill in the art of plant breeding would know how toevaluate the traits of two plant varieties to determine if there is nosignificant difference between the two traits expressed by thosevarieties. For example, see Fehr, Walt, Principles of CultivarDevelopment, p. 261-286 (1987) which is incorporated herein byreference. Mean trait values may be used to determine whether traitdifferences are significant, and preferably the traits are measured onplants grown under the same environmental conditions. Once such avariety is developed its value is substantial since it is important toadvance the germplasm base as a whole in order to maintain or improvetraits such as yield, disease resistance, pest resistance, and plantperformance in extreme weather conditions.

The goal of soybean breeding is to develop new, unique and superiorsoybean varieties. In practical application of a chosen soybean breedingprogram, the breeder initially selects and crosses two or more parentalvarieties, followed by repeated selfing and selection, producing manynew genetic combinations. Two breeders will never develop the samevariety, or even very similar varieties, having the same soybean traits.

Each year, the plant breeder selects the germplasm to advance to thenext generation. This germplasm is grown under unique and differentgeographical, climatic and soil conditions, and further selections arethen made during and at the end of the growing season.

Proper testing should detect major faults and establish the level ofsuperiority or improvement over current varieties. In addition toshowing superior performance, there must be a demand for a new variety.The new variety must be compatible with industry standards, or mustcreate a new market. The introduction of a new variety may incuradditional costs to the seed producer, the grower, processor andconsumer, for special advertising and marketing, altered seed andcommercial production practices, and new product utilization. Thetesting preceding release of a new variety should take intoconsideration research and development costs as well as technicalsuperiority of the final variety. For seed-propagated varieties, it mustbe feasible to produce seed easily and economically. Preferably residualheterozygosity should not exceed 5%.

These processes, which lead to the final step of marketing anddistribution, can take from six to twelve years from the time the firstcross is made. Therefore, development of new varieties is atime-consuming process that requires precise forward planning, efficientuse of resources, and a minimum of changes in direction.

Soybean (Glycine max), is an important and valuable field crop. Thus, acontinuing goal of soybean breeders is to develop stable, high yieldingsoybean varieties that are agronomically sound. The reasons for thisgoal are obviously to maximize the amount of grain produced on the landused and to supply food for both animals and humans. To accomplish thisgoal, the soybean breeder must select and develop soybean plants thathave the traits that result in superior varieties.

Pioneer soybean research staff creates over 500,000 potential newvarieties each year. Of those new varieties, less than 50 and morecommonly less than 25 are actually selected for commercial use.

SUMMARY OF INVENTION

According to the invention, there is provided a novel soybean variety,designated 91B42. This invention thus relates to the seeds of soybeanvariety 91B42, to the plants of soybean 91B42 to plant parts of soybeanvariety 91B42 and to methods for producing a soybean plant produced bycrossing soybean variety 91B42 with another soybean plant, using 91B42as either the male or the female parent. This invention also relates tomethods for producing a soybean plant containing in its genetic materialone or more transgenes and to the transgenic soybean plants and plantparts produced by those methods. This invention also relates to soybeanvarieties or breeding varieties and plant parts derived from soybeanvariety 91B42, to methods for producing other soybean varieties, linesor plant parts derived from soybean variety 91B42 and to the soybeanplants, varieties, and their parts derived from use of those methods.This invention further relates to soybean seeds, plants, and plant partsproduced by crossing the soybean variety 91B42 with another soybeanvariety. Soybean variety 91B42 demonstrates a unique combination oftraits, which include high yield potential, excellent resistance to race3 of Soybean Cyst Nematode, multi-race Phytophthora root rot resistancewhich includes resistance to race 25 of Phytophthora megasperma,excellent resistance to Brown Stem Rot, very good iron-deficiencytolerance, relative maturity group 1, sub-group 4, and particularlyadapted to Canada, Italy, and the North Central and Eastern areas of theUnited States. The combination of disease resistances offered by soybeanvariety 91B42 is highly unique and offers a large benefit.

Definitions

Certain definitions used in the specification are provided below. Alsoin the examples which follow, a number of terms are used. In order toprovide a clear and consistent understanding of the specification andclaims, including the scope to be given such terms, the followingdefinitions are provided:

ALLELE=any of one or more alternative forms of a genetic sequence. In adiploid cell or organism, the two alleles of a given sequence occupycorresponding loci on a pair of homologous chromosomes.

BACKCROSSING=Process in which a breeder crosses a progeny variety backto one of the parental genotypes one or more times.

BREEDING=The genetic manipulation of living organisms.

BU/A=Bushels per Acre. The seed yield in bushels/acre is the actualyield of the grain at harvest.

BSR=Brown Stem Rot Tolerance. This is a visual disease score from 1 to 9comparing all genotypes in a given test. The score is based on leafsymptoms of yellowing and necrosis caused by brown stem rot. A score of9 indicates no symptoms. Visual scores range down to a score of 1 whichindicates severe symptoms of leaf yellowing and necrosis.

CNKR=Stem Canker Tolerance. This is a visual disease score from 1 to 9comparing all genotypes in a given test. The score is based uponpremature plant death. A score of 9 indicates no symptoms, whereas ascore of 1 indicates the entire experimental unit died very early.

COTYLEDON=A cotyledon is a type of seed leaf. The cotyledon contains thefood storage tissues of the seed.

ELITE VARIETY=A variety that is sufficiently homozygous and homogeneousto be used for commercial grain production. An elite variety may also beused in further breeding.

EMBRYO=The embryo is the small plant contained within a mature seed.

EMGSC=Emergence Score. The percentage of emerged plants in a plotrespective to the number of seeds planted.

F₃=This symbol denotes a generation resulting from the selfing of the F₂generation along with selection for type and rogueing of off-types. The“F” number is a term commonly used in genetics, and designates thenumber of the filial generation. The “F₃” generation denotes theoffspring resulting from the selfing or self mating of members of thegeneration having the next lower “F” number, viz. the F₂ generation.

FEC=Iron-deficiency Chlorosis. Plants are scored 1 to 9 based on visualobservations. A score of 1 indicates the plants are dead or dying fromiron-deficiency chlorosis, a score of 5 means plants have intermediatehealth with some leaf yellowing and a score of 9 means no stunting ofthe plants or yellowing of the leaves. Plots are usually scored in midJuly.

FECL=Iron-deficiency Chlorosis. Plants are scored 1 to 9 based on visualobservations. A score of 1 indicates the plants are dead or dying fromiron-deficiency chlorosis, a score of 5 means plants have intermediatehealth with some leaf yellowing and a score of 9 means no stunting ofthe plants or yellowing of the leaves. Plots are scored around midAugust.

FEY=Frogeye Tolerance. This is a visual disease score from 1 to 9comparing all genotypes in a given test. The score is based upon leaflesions. A score of 9 indicates no lesions, whereas a score of 1indicates severe leaf necrosis.

GENOTYPE=Refers to the genetic constitution of a cell or organism.

HABIT=This refers to the physical appearance of a plant. It can bedeterminate, semi-determinate, intermediate, or indeterminate. Insoybeans, indeterminate varieties are those in which stem growth is notlimited by formation of a reproductive structure (i.e., flowers, podsand seeds) and hence growth continues throughout flowering and duringpart of pod filling. The main stem will develop and set pods over aprolonged period under favorable conditions. In soybeans, determinatevarieties are those in which stem growth ceases at flowering time. Mostflowers develop simultaneously, and most pods fill at approximately thesame time. The terms semi-determinate and intermediate are also used todescribe plant habit and are defined in Bernard, R. L. 1972. “Two genesaffecting stem termination in soybeans.” Crop Science 12:235-239;Woodworth, C. M. 1932. “Genetics and breeding in the improvement of thesoybean.” Bull. Agric. Exp. Stn. (Illinois) 384:297-404; Woodworth, C.M. 1933. “Genetics of the soybean.” J. Am. Soc. Agron. 25:36-51.

HGT=Plant Height. Plant height is taken from the top of the soil to toppod of the plant and is measured in inches.

HILUM=This refers to the scar left on the seed which marks the placewhere the seed was attached to the pod prior to it (the seed) beingharvested.

HYPL=Hypocotyl Elongation. This score indicates the ability of the seedto emerge when planted 3″ deep in sand pots and with a controlledtemperature of 25° C. The number of plants that emerge each day arecounted. Based on this data, each genotype is given a 1 to 9 score basedon its rate of emergence and percent of emergence. A score of 9indicates an excellent rate and percent of emergence, an intermediatescore of 5 indicates average ratings and a 1 score indicates a very poorrate and percent of emergence.

HYPOCOTYL=A hypocotyl is the portion of an embryo or seedling betweenthe cotyledons and the root. Therefore, it can be considered atransition zone between shoot and root.

LDGSEV=Lodging Resistance. Lodging is rated on a scale of 1 to 9. Ascore of 9 indicates erect plants. A score of 5 indicates plants areleaning at a 45° angle in relation to the ground and a score of 1indicates plants are laying on the ground.

LEAFLETS=These are part of the plant shoot, and they manufacture foodfor the plant by the process of photosynthesis.

LINKAGE=Refers to a phenomenon wherein alleles on the same chromosometend to segregate together more often than expected by chance if theirtransmission was independent.

LINKAGE DISEQUILIBRIUM=Refers to a phenomenon wherein alleles tend toremain together in linkage groups when segregating from parents tooffspring, with a greater frequency than expected from their individualfrequencies.

LLE=Linoleic Acid Percent. Linoleic acid is one of the five mostabundant fatty acids in soybean seeds. It is measured by gaschromatography and is reported as a percent of the total oil content.

LLN=Linolenic Acid Percent. Linolenic acid is one of the five mostabundant fatty acids in soybean seeds. It is measured by gaschromatography and is reported as a percent of the total oil content.

MAT ABS=Absolute Maturity. This term is defined as the length of timefrom planting to complete physiological development (maturity). Theperiod from planting until maturity is reached is measured in days,usually in comparison to one or more standard varieties. Plants areconsidered mature when 95% of the pods have reached their mature color.

MATURITY GROUP=This refers to an agreed-on industry division of groupsof varieties, based on the zones in which they are adapted primarilyaccording to day length or latitude. They consist of very long daylength varieties (Groups 000, 00, 0), and extend to very short daylength varieties (Groups VII, VIII, IX, X).

OIL=Oil Percent. Soybean seeds contain a considerable amount of oil. Oilis measured by NIR spectrophotometry, and is reported on an as ispercentage basis.

OLC=Oleic Acid Percent. Oleic acid is one of the five most abundantfatty acids in soybean seeds. It is measured by gas chromatography andis reported as a percent of the total oil content.

PEDIGREE DISTANCE=Relationship among generations based on theirancestral links as evidenced in pedigrees. May be measured by thedistance of the pedigree from a given starting point in the ancestry.

PLM=Palmitic Acid Percent. Palmitic acid is one of the five mostabundant fatty acids in soybean seeds. It is measured by gaschromatography and is reported as a percent of the total oil content.

POD=This refers to the fruit of a soybean plant. It consists of the hullor shell (pericarp) and the soybean seeds.

PRT=Phytophthora Tolerance. Tolerance to Phytophthora root rot is ratedon a scale of 1 to 9, with a score of 9 being the best or highesttolerance ranging down to a score of 1 which indicates the plants haveno tolerance to Phytophthora.

PRMMAT=Predicted Relative Maturity. Soybean maturities are divided intorelative maturity groups. In the United States the most common maturitygroups are 00 through VIII. Within maturity groups 00 through V aresub-groups. A sub-group is a tenth of a relative maturity group. Withinnarrow comparisons, the difference of a tenth of a relative maturitygroup equates very roughly to a day difference in maturity at harvest.

PRO=Protein Percent. Soybean seeds contain a considerable amount ofprotein. Protein is generally measured by NIR spectrophotometry, and isreported on an as is percentage basis.

PUBESCENCE=This refers to a covering of very fine hairs closely arrangedon the leaves, stems and pods of the soybean plant.

RKI=Root-knot Nematode, Southern. This is a visual disease score from 1to 9 comparing all genotypes in a given test. The score is based upondigging plants to visually score the roots for presence or absence ofgalling. A score of 9 indicates that there is no galling of the roots, ascore of 1 indicates large severe galling cover most of the root systemwhich results in pre-mature death from decomposing of the root system.

RKA=Root-knot Nematode, Peanut. This is a visual disease score from 1 to9 comparing all genotypes in a given test. The score is based upondigging plants to look at the roots for presence or absence of galling.A score of 9 indicates that there is no galling of the roots, a score of1 indicates large severe galling cover most of the root system whichresults in pre-mature death from decomposing of the root system.

SD VIG=Seedling Vigor. The score is based on the speed of emergence ofthe plants within a plot relative to other plots within an experiment. Ascore of 9 indicates that 90% of plants growing have expanded firstleaves. A score of 1 indicates no plants have expanded first leaves.

SDS=Sudden Death Syndrome. Tolerance to Sudden Death Syndrome is ratedon a scale of 1 to 9, with a score of 1 being very susceptible rangingup to a score of 9 being tolerant.

S/LB=Seeds per Pound. Soybean seeds vary in seed size, therefore, thenumber of seeds required to make up one pound also varies. This affectsthe pounds of seed required to plant a given area, and can also impactend uses.

SHATTR=Shattering. This refers to the amount of pod dehiscence prior toharvest. Pod dehiscence involves seeds falling from the pods to thesoil. This is a visual score from 1 to 9 comparing all genotypes withina given test. A score of 9 means pods have not opened and no seeds havefallen out. A score of 5 indicates approximately 50% of the pods haveopened, with seeds falling to the ground and a score of 1 indicates 100%of the pods are opened.

SHOOTS=These are a portion of the body of the plant. They consist ofstems, petioles and leaves.

STC=Stearic Acid Percent. Stearic acid is one of the five most abundantfatty acids in soybean seeds. It is measured by gas chromatography andis reported as a percent of the total oil content.

WH MD=White Mold Tolerance. This is a visual disease score from 1 to 9comparing all genotypes in a given test. The score is based uponobservations of mycelial growth and death of plants. A score of 9indicates no symptoms. Visual scores of 1 indicate complete death of theexperimental unit.

For traits rated on a scoring system of 1 to 9, a score of 6 or betteris considered good, a score of 7 or better is considered very good, anda score of 8 or better is considered excellent.

Definitions for Area of Adaptability

When referring to area of adaptability, such term is used to describethe location with the environmental conditions that would be well suitedfor this soybean variety. Area of adaptability is based on a number offactors, for example: days to maturity, insect resistance, diseaseresistance, and drought resistance. Area of adaptability does notindicate that the soybean variety will grow in every location within thearea of adaptability or that it will not grow outside the area.

Midwest: Iowa and Missouri

Heartland: Illinois and the western half of Indiana

Plains: ⅔ of the eastern parts of South Dakota and Nebraska

North Central: Minnesota, Wisconsin, the Upper Peninsula of Michigan,and the eastern half of North Dakota

Mideast: Michigan, Ohio, and the eastern half of Indiana

Eastern: Pennsylvania, Delaware, Maryland, Rhode Island, New Jersey,Connecticut, Massachusetts, New York, Vermont, and Maine

Southern: Virginia, West Virginia, Tennessee, Kentucky, Arkansas, NorthCarolina, South Carolina, Georgia, Florida, Alabama, Mississippi, andLouisiana

Western: Texas, Kansas, Colorado, Oklahoma, New Mexico, Arizona, Utah,Nevada, California, Washington, Oregon, Montana, Idaho, Wyoming, thewestern half of North Dakota, and the western ⅓ South Dakota andNebraska

PMG infested soils: soils containing Phytophthora megasperma

Narrow rows: 7″ and 15″ row spacing

High yield environments: areas which lack normal stress for example theyhave sufficient rainfall, water drainage, low disease pressure, and lowweed pressure

Tough environments: areas which have stress challenges, opposite of ahigh yield environment

DETAILED DESCRIPTION OF INVENTION

A soybean variety needs to be homogeneous, substantially homozygous andreproducible to be useful as a commercial variety. There are manyanalytical methods available to determine the homozygotic stability,phenotypic stability, and identity of these varieties.

The oldest and most traditional method of analysis is the observation ofphenotypic traits. The data is usually collected in field experimentsover the life of the soybean plants to be examined. Phenotypiccharacteristics most often observed are for traits associated with seedyield, seed protein and oil content, lodging resistance, diseaseresistance, maturity, plant height, shattering resistance, etc.

In addition to phenotypic observations, the genotype of a plant can alsobe examined. There are many laboratory-based techniques available forthe analysis, comparison and characterization of plant genotype; amongthese are Isozyme Electrophoresis, Restriction Fragment LengthPolymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs),Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA AmplificationFingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs),Amplified Fragment Length Polymorphisms (AFLPs), Simple Sequence Repeats(SSRs) which are also referred to as Microsatellites, and SingleNucleotide Polymorphisms (SNPs).

Isozyme Electrophoresis and RFLPs have been widely used to determinegenetic composition. Shoemaker and Olsen, ((1993) Molecular Linkage Mapof Soybean (Glycine max L. Merr.). p. 6.131-6.138. In S. J. O'Brien(ed.) Genetic Maps. Locus Maps of Complex Genomes. Cold Spring HarborLaboratory Press. Cold Spring Harbor, N.Y.), developed a moleculargenetic linkage map that consisted of 25 linkage groups with about 365RFLP, 11 RAPD (random amplified polymorphic DNA), three classicalmarkers, and four isozyme loci. See also, Shoemaker R. C. 1994 RFLP Mapof Soybean. P. 299-309 In R. L. Phillips and I. K. Vasil (ed.) DNA-basedmarkers in plants. Kluwer Academic Press Dordrecht, the Netherlands.

SSR technology is currently the most efficient and practical markertechnology; more marker loci can be routinely used and more alleles permarker locus can be found using SSRs in comparison to RFLPs. For exampleDiwan and Cregan, described a highly polymorphic microsatellite loci inSoybean with as many as 26 alleles. (Diwan, N., and P. B. Cregan 1997Automated sizing of fluorescent-labeled simple sequence repeat (SSR)markers to assay genetic variation in Soybean Theor. Appl. Genet.95:220-225). Single Nucleotide Polymorphisms may also be used toidentify the unique genetic composition of the invention and progenyvarieties retaining that unique genetic composition. Various molecularmarker techniques may be used in combination to enhance overallresolution.

Soybean DNA molecular marker linkage maps have been rapidly constructedand widely implemented in genetic studies. One such study is describedin Cregan et. al, “An Integrated Genetic Linkage Map of the SoybeanGenome” Crop Science 39:1464-1490 (1999). Sequences and PCR conditionsof SSR Loci in Soybean as well as the most current genetic map may belocated on the internet at soybase.agron.iastate.edu or atsoybase.ncgr.org/the disclosures of which are incorporated herein byreference.

The variety of the invention has shown uniformity and stability for alltraits, as described in the following variety description information.It has been self-pollinated a sufficient number of generations, withcareful attention to uniformity of plant type to ensure homozygosity andphenotypic stability. The variety has been increased with continuedobservation for uniformity. No variant traits have been observed or areexpected in 91B42, as described in Table 1 (Variety DescriptionInformation).

Soybean variety 91B42 is a purple flowered soybean variety with tawnypubescence and black colored hila. Soybean variety 91B42 is in therelative maturity group 1, sub-group 4, and is particularly adapted toCanada, Italy, and the North Central and Eastern areas of the UnitedStates. Variety 91B42 further demonstrates excellent resistance to race3 of Soybean Cyst Nematode, multi-race Phytophthora root rot resistancewhich includes resistance to race 25 of Phytophthora megasperma,excellent resistance to Brown Stem Rot, and very good iron-deficiencytolerance. This variety does well in Soybean Cyst Nematode andPhytophthora megasperma infected soils.

91B42 possesses the unique combination of resistance to races 1-26, 28,and 33-44 of Phytophthora megasperma in addition to resistance to race 3of Soybean Cyst Nematode. Resistance to races 1-11, 13-15, 17, 18,21-24, 26, 33, 36-38 and 42-44 of Phytophthora megasperma are governedby the RPS 1-K gene, and resistance to races 1-4, 10, 12, 14-16, 18-21,25, 28, 33-35, and 38-44 of Phytophthora megasperma are governed by theRPS 6 gene. As used herein the term “multi-race Phytophthora resistance”shall mean resistance to races 1-26, 28, and 33-44 as conferred by theRPS 1k and RPS6 genes. Resistance to race 3 of Soybean Cyst Nematode isa quantitative trait.

Soybean variety 91B42, being substantially homozygous, can be reproducedby planting seeds of the variety, growing the resulting soybean plantsunder self-pollinating or sib-pollinating conditions, and harvesting theresulting seed, using techniques familiar to the agricultural arts.

TABLE 1 Variety Description Information 91B42 A. Mature SeedCharacteristics: Seed Coat Color: yellow Seed Size (grams per 100seeds): 18 Hilum Color: black Seed Shape: elongated Seed Coat Luster:dull B. Leaf: Leaflet Shape: ovate C. Plant Characteristics: FlowerColor: purple Pod Color: tan Cotyledon Color: yellow Hypocotyl Color:dark purple Plant Pubescence Color: tawny Plant Habit: indeterminateMaturity Group: 1 Maturity Sub-Group: 4 D. Fungal Diseases (S =susceptible R = resistant) Phytophthora Rot (Phytophthora megaspermavar. sojae): Race 5: R  Race 7: R  Race 25: R E. Nematode Diseases (S =susceptible R = resistant) Soybean Cyst Nematode Race 3: R (score of 8)Race 14: (score of 6) F. Iron Chlorosis: Very Good tolerance to irondeficiency chlorosis G. Seed Peroxidase Activity: high Publicationsuseful as references in interpreting Table 1 include: Caldwell, B. E.ed. 1973. “Soybeans: Improvement, Production, and Uses” Amer. Soc.Agron. Monograph No. 16; Buttery, B. R., and R. I. Buzzell 1968.“Peroxidase Activity in Seed of Soybean Varieties” Crop Sci. 8: 722-725;Hymowitz, T. 1973. “Electrophoretic analysis of SBTI-A2 in the USDASoybean Germplasm Collection” Crop Sci., 13: 420-421; Payne R. C., andL.F. Morris, 1976. “Differentiation of Soybean Varieties by SeedlingPigmentation Patterns” J. Seed. Technol. 1: 1-19. The disclosures ofwhich are each incorporated by reference in their entirety.

FURTHER EMBODIMENTS OF THE INVENTION

This invention also is directed to methods for producing a soybean plantby crossing a first parent soybean plant with a second parent soybeanplant wherein the first or second parent soybean plant is a soybeanplant of the variety 91B42. Further, both first and second parentsoybean plants can come from the soybean variety 91B42. Still further,this invention also is directed to methods for producing 91B42-derivedsoybean plant by crossing soybean variety 91B42 with a soybean plant andgrowing the progeny seed, and repeating the crossing and growing stepswith the 91B42-derived soybean plant from 1 to 2 times, 1 to 3 times, 1to 4 times, or 1 to 5 times. Thus, any such methods using soybeanvariety 91B42 are part of this invention: selfing, backcrosses, hybridproduction, crosses to populations, and the like. All plants producedusing soybean variety 91B42 as a parent are within the scope of thisinvention, including plants derived from soybean variety 91B42. Thisincludes varieties essentially derived from variety 91B42 with the term“essentially derived variety” having the meaning ascribed to such termin 7 U.S.C. § 2104(a)(3) of the Plant Variety Protection Act, whichdefinition is hereby incorporated by reference. The invention alsoincludes progeny plants and parts thereof with at least one ancestorthat is 91B42, and more specifically, where the pedigree of the progenyincludes 1, 2, 3, 4, and/or 5 or less cross-pollinations to a soybeanplant other than 91B42 or a plant that has 91B42 as a progenitor. Allbreeders of ordinary skill in the art maintain pedigree records of theirbreeding programs. These pedigree records contain a detailed descriptionof the breeding process, including a listing of all parental varietiesused in the breeding process and information on how such variety wasused. Thus, a breeder would know if 91B42 were used in the developmentof a progeny variety, and would also know how many crosses to a plant orvariety other than 91B42 or a plant or variety with 91B42 as aprogenitor were made in the development of any progeny variety. Thesoybean variety may also be used in crosses with other, differentsoybean plant to produce first generation (F₁) soybean seeds and plantswith superior characteristics.

Specific methods and products produced using soybean variety 91B42 inplant breeding are encompassed within the scope of the invention listedabove.

One such embodiment is a method for developing a 91B42 progeny soybeanplant in a soybean plant breeding program comprising: obtaining thesoybean plant, or its parts, or variety 91B42 utilizing said plant orplant parts as a source of breeding material; and selecting a 91B42progeny plant with molecular markers in common with 91B42 and/or withmorphological and/or physiological characteristics selected from thecharacteristics listed in Tables 1 or 2. Breeding steps that may be usedin the soybean plant breeding program include pedigree breeding,backcrossing, mutation breeding, and recurrent selection. In conjunctionwith these steps, techniques such as restriction fragment polymorphismenhanced selection, genetic marker enhanced selection (for example SSRmarkers), and the making of double haploids may be utilized.

Another such embodiment is the method of crossing soybean variety 91B42with another soybean plant, such as a different soybean variety, to forma first generation population of F1 hybrid plants. The population offirst generation F1 hybrid plants produced by this method is also anembodiment of the invention. This first generation population of F1plants will comprise an essentially complete set of the alleles ofsoybean variety 91B42. One of ordinary skill in the art can utilizeeither breeder books or molecular methods to identify a particular F1hybrid plant produced using soybean variety 91B42, and any suchindividual plant is also encompassed by this invention. Theseembodiments also cover use of these methods with transgenic or singlegene conversions of soybean variety 91B42.

Another such embodiment of this invention is a method of using soybeanvariety 91B42 in breeding that involves the repeated backcrossing tosoybean variety 91B42 any number of times. Using backcrossing methods,or even the tissue culture and transgenic methods described herein, thesingle gene conversion methods described herein, or other breedingmethods known to one of ordinary skill in the art, one can developindividual plants, plant cells, and populations of plants that retain atleast 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 79%, 80%,81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98%, 99% or 99.5% genetic contribution from soybeanvariety 91B42. The percentage of the genetics retained in the progenymay be measured by either pedigree analysis or through the use ofgenetic techniques such as molecular markers or electrophoresis. Inpedigree analysis, on average 50% of the starting germplasm would bepassed to the progeny variety after one cross to another variety, 25%after another cross to a different variety, and so on. Molecular markerscould also be used to confirm and/or determine the pedigree of theprogeny variety.

One method for producing a variety derived from soybean variety 91B42 isas follows. One of ordinary skill in the art would obtain a seed fromthe cross between soybean variety 91B42 and another variety of soybean,such as an elite variety. The F1 seed derived from this cross would begrown to form a homogeneous population. The F1 seed would containessentially all of the alleles from variety 91B42 and essentially all ofthe alleles from the other soybean variety. The F1 nuclear genome wouldbe made-up of 50% variety 91B42 and 50% of the other elite variety. TheF1 seed would be grown and allowed to self, thereby forming F2 seed. Onaverage the F2 seed would have derived 50% of its alleles from variety91B42 and 50% from the other soybean variety, but many individual plantsfrom the population would have a greater percentage of their allelesderived from 91B42 (Wang J. and R. Bernardo, 2000, Crop Sci. 40:659-665and Bernardo, R. and A. L. Kahler, 2001, Theor. Appl. Genet102:986-992). Molecular markers of 91B42 could be used to select andretain those varieties with high similarity to 91B42. The F2 seed wouldbe grown and selection of plants would be made based on visualobservation, markers and/or measurement of traits. The traits used forselection may be any 91B42 trait described in this specification,including the soybean variety 91B42 traits of high yield potential,excellent resistance to race 3 of Soybean Cyst Nematode, multi-racePhytophthora root rot resistance which includes resistance to race 25 ofPhytophthora megasperma, excellent resistance to Brown Stem Rot, verygood iron-deficiency tolerance, relative maturity group I, sub-group 4,and particularly adapted to Canada, Italy, and the North Central andEastern areas of the United States.

Such traits may also be the good general or specific combining abilityof 91B42. The 91B42 progeny plants that exhibit one or more of thedesired 91B42 traits, such as those listed above, would be selected andeach plant would be harvested separately. This F3 seed from each plantwould be grown in individual rows and allowed to self. Then selectedrows or plants from the rows would be harvested individually. Theselections would again be based on visual observation, markers and/ormeasurements for desirable traits of the plants, such as one or more ofthe desirable 91B42 traits listed above. The process of growing andselection would be repeated any number of times until a 91B42 progenyplant is obtained. The 91B42 progeny plant would contain desirabletraits derived from soybean plant 91B42, some of which may not have beenexpressed by the other variety to which soybean variety 91B42 wascrossed and some of which may have been expressed by both soybeanvarieties but now would be at a level equal to or greater than the levelexpressed in soybean variety 91B42. However, in each case the resultingprogeny variety would benefit from the efforts of the inventor(s), andwould not have existed but for the inventor(s) work in creating 91B42.The 91B42 progeny plants would have, on average, 50% of their genesderived from variety 91B42, but many individual plants from thepopulation would have a greater percentage of their alleles derived from91B42. This breeding cycle, of crossing and selfing, and optionalselection, may be repeated to produce another population of 91B42progeny plants with, on average, 25% of their genes derived from variety91B42, but, again, many individual plants from the population would havea greater percentage of their alleles derived from 91B42. Anotherembodiment of the invention is a 91B42 progeny plant that has receivedthe desirable 91B42 traits listed above through the use of 91B42, whichtraits were not exhibited by other plants used in the breeding process.

The previous example can be modified in numerous ways, for instanceselection may or may not occur at every selfing generation, selectionmay occur before or after the actual self-pollination process occurs, orindividual selections may be made by harvesting individual pods, plants,rows or plots at any point during the breeding process described. Inaddition, double haploid breeding methods may be used at any step in theprocess. The population of plants produced at each and any cycle ofbreeding is also an embodiment of the invention, and on average eachsuch population would predictably consist of plants containingapproximately 50% of its genes from variety 91B42 in the first breedingcycle, 25% of its genes from variety 91B42 in the second breeding cycle,12.5% of its genes from variety 91B42 in the third breeding cycle and soon. However, in each case the use of 91B42 provides a substantialbenefit. The linkage groups of 91B42 would be retained in the progenyvarieties, thus it provides a significant advantage to use 91B42 asstarting material to produce a variety that retains desired genetics ortraits of 91B42.

Another embodiment of this invention is the method of obtaining asubstantially homozygous 91B42 progeny plant by obtaining a seed fromthe cross of 91B42 and another soybean plant and applying double haploidmethods to the F1 seed or F1 plant or to any successive filialgeneration. Based on studies in maize and currently being conducted insoybean, such methods would decrease the number of generations requiredto produce a variety with similar genetics or characteristics to 91B42.See Bernardo, R. and Kahler, A. L., Theor. Appl. Genet, 102:986-992(2001).

A further embodiment of the invention is a single gene conversion of91B42. A single gene conversion occurs when DNA sequences are introducedthrough traditional (non-transformation) breeding techniques, such asbackcrossing (Hallauer et al., 1988). DNA sequences, whether naturallyoccurring or transgenes, may be introduced using these traditionalbreeding techniques. The term single gene conversion is also referred toin the art as a single locus conversion. Reference is made to US2002/0062506A1 for a detailed discussion of single locus conversions andtraits that may be incorporated into 91B42 through single geneconversion. Desired traits transferred through this process include, butare not limited to, nutritional enhancements, industrial enhancements,disease resistance, insect resistance, herbicide resistance and yieldenhancements. The trait of interest is transferred from the donor parentto the recurrent parent, in this case, the soybean plant disclosedherein. Single gene traits may result from either the transfer of adominant allele or a recessive allele. Selection of progeny containingthe trait of interest is accomplished by direct selection for a traitassociated with a dominant allele. Selection of progeny for a trait thatis transferred via a recessive allele, requires growing and selfing thefirst backcross generation to determine which plants carry the recessivealleles. Recessive traits may require additional progeny testing insuccessive backcross generations to determine the presence of the geneof interest. Along with selection for the trait of interest, progeny areselected for the phenotype of the recurrent parent. It should beunderstood that occasionally additional polynucleotide sequences orgenes are transferred along with the single gene conversion trait ofinterest. A progeny comprising at least 98%, 99%, 99.5% and 99.9% of thegenes from the recurrent parent, the soybean variety disclosed herein,plus containing the single gene conversion trait or traits of interest,is considered to be a single gene conversion of soybean variety 91B42.

This invention is also directed to the use of variety 91B42 in tissueculture. Tissue culture of various tissues of soybeans and regenerationof plants therefrom is well known and widely published. For example,reference may be had to Komatsuda, T. et al., “Genotype X SucroseInteractions for Somatic Embryogenesis in Soybean,” Crop Sci. 31:333-337(1991); Stephens, P. A. et al., “Agronomic Evaluation ofTissue-Culture-Derived Soybean Plants,” Theor. Appl. Genet. (1991)82:633-635; Komatsuda, T. et al., “Maturation and Germination of SomaticEmbryos as Affected by Sucrose and Plant Growth Regulators in SoybeansGlycine gracilis Skvortz and Glycine max (L.) Merr.,” Plant Cell, Tissueand Organ Culture, 28:103-113 (1992); Dhir, S. et al., “Regeneration ofFertile Plants from Protoplasts of Soybean (Glycine max L. Merr.):Genotypic Differences in Culture Response,” Plant Cell Reports (1992)11:285-289; Pandey, P. et al., “Plant Regeneration from Leaf andHypocotyl Explants of Glycine wightii (W. and A.) VERDC. var.Iongicauda,” Japan J. Breed. 42:1-5 (1992); and Shetty, K., et al.,“Stimulation of In Vitro Shoot Organogenesis in Glycine max (Merrill.)by Allantoin and Amides,” Plant Science 81:(1992) 245-251; as well asU.S. Pat. No. 5,024,944, issued Jun. 18, 1991 to Collins et al. and U.S.Pat. No. 5,008,200, issued Apr. 16, 1991 to Ranch et al., thedisclosures of which are hereby incorporated herein in their entirety byreference. Thus, another aspect of this invention is to provide cellswhich upon growth and differentiation produce soybean plants having thephysiological and morphological characteristics of soybean variety91B42.

As used herein, the term plant includes plant protoplasts, plant celltissue cultures from which soybean plants can be regenerated, plantcalli, plant clumps, and plant cells that are intact in plants or partsof plants, such as embryos, pollen, ovules, seed, flowers, pods, leaves,roots, root tips, anthers, and the like.

All plants produced using soybean variety 91B42 as a parent are withinthe scope of this invention, including those developed from varietiesderived from soybean variety 91B42. Advantageously, the soybean varietycould be used in crosses with other, different, soybean plants toproduce first generation (F₁) soybean hybrid seeds and plants withsuperior characteristics. The variety of the invention can also be usedfor transformation where exogenous genes are introduced and expressed bythe variety of the invention. Genetic variants created either throughtraditional breeding methods using variety 91B42 or throughtransformation of 91B42 by any of a number of protocols known to thoseof skill in the art are intended to be within the scope of thisinvention.

Transformation of Soybean

The advent of new molecular biological techniques have allowed theisolation and characterization of genetic elements with specificfunctions, such as encoding specific protein products. Scientists in thefield of plant biology developed a strong interest in engineering thegenome of plants to contain and express foreign genetic elements, oradditional, or modified versions of native or endogenous geneticelements in order to alter the traits of a plant in a specific manner.Any DNA sequences, whether from a different species or from the samespecies, that are inserted into the genome using transformation arereferred to herein collectively as “transgenes”. Over the last fifteento twenty years several methods for producing transgenic plants havebeen developed, and the present invention, in particular embodiments,also relates to transformed versions of the soybean variety 91B42.

Numerous methods for plant transformation have been developed, includingbiological and physical, plant transformation protocols. See, forexample, Miki et al., “Procedures for Introducing Foreign DNA intoPlants” in Methods in Plant Molecular Biology and Biotechnology, Glick,B. R. and Thompson, J. E. Eds. (CRC Press, Inc., Boca Raton, 1993) pages67-88. In addition, expression vectors and in vitro culture methods forplant cell or tissue transformation and regeneration of plants areavailable. See, for example, Gruber et al., “Vectors for PlantTransformation” in Methods in Plant Molecular Biology and Biotechnology,Glick, B. R. and Thompson, J. E. Eds. (CRC Press, Inc., Boca Raton,1993) pages 89-119.

The most prevalent types of plant transformation involve theconstruction of an expression vector. Such a vector comprises a DNAsequence that contains a gene under the control of or operatively linkedto a regulatory element, for example a promoter. The vector may containone or more genes and one or more regulatory elements.

Various genetic elements can be introduced into the plant genome usingtransformation. These elements include but are not limited to genes;coding sequences; inducible, constitutive, and tissue specificpromoters; enhancing sequences; and signal and targeting sequences. SeeU.S. Pat. No. 6,162,968, which is herein incorporated by reference.

A genetic trait which has been engineered into a particular soybeanplant using transformation techniques, could be moved into anothervariety using traditional breeding techniques that are well known in theplant breeding arts. For example, a backcrossing approach could be usedto move a transgene from a transformed soybean plant to an elite soybeanvariety and the resulting progeny would comprise a transgene. As usedherein, “crossing” can refer to a simple X by Y cross, or the process ofbackcrossing, depending on the context. The term “cross” excludes theprocesses of selfing or sibbing.

With transgenic plants according to the present invention, a foreignprotein can be produced in commercial quantities. Thus, techniques forthe selection and propagation of transformed plants, which are wellunderstood in the art, yield a plurality of transgenic plants which areharvested in a conventional manner, and a foreign protein then can beextracted from a tissue of interest or from total biomass. Proteinextraction from plant biomass can be accomplished by known methods whichare discussed, for example, by Heney and Orr, Anal. Biochem. 114:92-6(1981).

According to a preferred embodiment, the transgenic plant provided forcommercial production of foreign protein is a soybean plant. In anotherpreferred embodiment, the biomass of interest is seed. A genetic map canbe generated, primarily via conventional RFLP, PCR, and SSR analysis,which identifies the approximate chromosomal location of the integratedDNA molecule. For exemplary methodologies in this regard, see Glick andThompson, METHODS IN PLANT MOLECULAR BIOLOGY AND BIOTECHNOLOGY 269-284(CRC Press, Boca Raton, 1993). Map information concerning chromosomallocation is useful for proprietary protection of a subject transgenicplant. If unauthorized propagation is undertaken and crosses made withother germplasm, the map of the integration region can be compared tosimilar maps for suspect plants, to determine if the latter have acommon parentage with the subject plant. Map comparisons would involvehybridizations, RFLP, PCR, SSR and sequencing, all of which areconventional techniques.

Likewise, by means of the present invention, agronomic genes can beexpressed in transformed plants. More particularly, plants can begenetically engineered to express various phenotypes of agronomicinterest. Through the transformation of soybean the expression of genescan be modulated to enhance disease resistance, insect resistance,herbicide resistance, agronomic traits as well as grain quality traits.Transformation can also be used to insert DNA sequences which control orhelp control male-sterility. DNA sequences native to soybean as well asnon-native DNA sequences can be transformed into soybean and used tomodulate levels of native or non-native proteins. Anti-sense technology,various promoters, targeting sequences, enhancing sequences, and otherDNA sequences can be inserted into the soybean genome for the purpose ofmodulating the expression of proteins. Exemplary genes implicated inthis regard include, but are not limited to, those categorized below.

1. Genes that Confer Resistance to Pests or Disease and that Encode:

(A) Plant disease resistance genes. Plant defenses are often activatedby specific interaction between the product of a disease resistance gene(R) in the plant and the product of a corresponding avirulence (Avr)gene in the pathogen. A plant variety can be transformed with a clonedresistance gene to engineer plants that are resistant to specificpathogen strains. See, for example Jones et al., Science 266: 789 (1994)(cloning of the tomato Cf-9 gene for resistance to Cladosporium fulvum);Martin et al., Science 262:1432 (1993) (tomato Pto gene for resistanceto Pseudomonas syringae pv. tomato encodes a protein kinase); Mindrinoset al., Cell 78:1089 (1994) (Arabidopsis RSP2 gene for resistance toPseudomonas syringae).

(B) A gene conferring resistance to a pest, such as soybean cystnematode. See e.g. PCT Application WO96/30517; PCT ApplicationWO93/19181.

(C) A Bacillus thuringiensis protein, a derivative thereof or asynthetic polypeptide modeled thereon. See, for example, Geiser et al.,Gene 48:109 (1986), who disclose the cloning and nucleotide sequence ofa Bt δ-endotoxin gene. Moreover, DNA molecules encoding 8-endotoxingenes can be purchased from American Type Culture Collection (Manassas,Va.), for example, under ATCC Accession Nos. 40098, 67136, 31995 and31998. Other examples of Bacillus thuringiensis transgenes beinggenetically engineered are given in the following patents and hereby areincorporated by reference: U.S. Pat. Nos. 5,188,960; 5,689,052;5,880,275; and WO 97/40162.

(D) A lectin. See, for example, the disclosure by Van Damme et al.,Plant Molec. Biol. 24:25 (1994), who disclose the nucleotide sequencesof several Clivia miniata mannose-binding lectin genes.

(E) A vitamin-binding protein such as avidin. See PCT ApplicationUS93/06487, the contents of which are hereby incorporated by reference.The application teaches the use of avidin and avidin homologues aslarvicides against insect pests.

(F) An enzyme inhibitor, for example, a protease or proteinase inhibitoror an amylase inhibitor. See, for example, Abe et al., J. Biol. Chem.262:16793 (1987) (nucleotide sequence of rice cysteine proteinaseinhibitor), Huub et al., Plant Molec. Biol. 21:985 (1993) (nucleotidesequence of cDNA encoding tobacco proteinase inhibitor 1), Sumitani etal., Biosci. Biotech. Biochem. 57:1243 (1993) (nucleotide sequence ofStreptomyces nitrosporeus α-amylase inhibitor) and U.S. Pat. No.5,494,813 (Hepher and Atkinson, issued Feb. 27, 1996).

(G) An insect-specific hormone or pheromone such as an ecdysteroid andjuvenile hormone, a variant thereof, a mimetic based thereon, or anantagonist or agonist thereof. See, for example, the disclosure byHammock et al., Nature 344:458 (1990), of baculovirus expression ofcloned juvenile hormone esterase, an inactivator of juvenile hormone.

(H) An insect-specific peptide or neuropeptide which, upon expression,disrupts the physiology of the affected pest. For example, see thedisclosures of Regan, J. Biol. Chem. 269:9 (1994) (expression cloningyields DNA coding for insect diuretic hormone receptor), and Pratt etal., Biochem. Biophys. Res. Comm. 163:1243 (1989) (an allostatin isidentified in Diploptera puntata). See also U.S. Pat. No. 5,266,317 toTomalski et al., who disclose genes encoding insect-specific, paralyticneurotoxins.

(I) An insect-specific venom produced in nature by a snake, a wasp, etc.For example, see Pang et al., Gene 116:165 (1992), for disclosure ofheterologous expression in plants of a gene coding for a scorpioninsectotoxic peptide.

(J) An enzyme responsible for an hyperaccumulation of a monoterpene, asesquiterpene, a steroid, hydroxamic acid, a phenylpropanoid derivativeor another non-protein molecule with insecticidal activity.

(K) An enzyme involved in the modification, including thepost-translational modification, of a biologically active molecule; forexample, a glycolytic enzyme, a proteolytic enzyme, a lipolytic enzyme,a nuclease, a cyclase, a transaminase, an esterase, a hydrolase, aphosphatase, a kinase, a phosphorylase, a polymerase, an elastase, achitinase and a glucanase, whether natural or synthetic. See PCTApplication WO 93/02197 in the name of Scott et al., which discloses thenucleotide sequence of a callase gene. DNA molecules which containchitinase-encoding sequences can be obtained, for example, from the ATCCunder Accession Nos. 39637 and 67152. See also Kramer et al., InsectBiochem. Molec. Bio1.23:691 (1993), who teach the nucleotide sequence ofa cDNA encoding tobacco hookworm chitinase, and Kawalleck et al., PlantMolec. Biol. 21:673 (1993), who provide the nucleotide sequence of theparsley ubi4-2 polyubiquitin gene.

(L) A molecule that stimulates signal transduction. For example, see thedisclosure by Botella et al., Plant Molec. Biol. 24:757 (1994), ofnucleotide sequences for mung bean calmodulin cDNA clones, and Griess etal., Plant Physiol. 104:1467 (1994), who provide the nucleotide sequenceof a maize calmodulin cDNA clone.

(M) A hydrophobic moment peptide. See PCT Application WO95/16776(disclosure of peptide derivatives of Tachyplesin which inhibit fungalplant pathogens) and PCT Application WO95/18855 (teaches syntheticantimicrobial peptides that confer disease resistance), the respectivecontents of which are hereby incorporated by reference.

(N) A membrane permease, a channel former or a channel blocker. Forexample, see the disclosure by Jaynes et al., Plant Sci. 89:43 (1993),of heterologous expression of a cecropin-β lytic peptide analog torender transgenic tobacco plants resistant to Pseudomonas solanacearum.

(O) A viral-invasive protein or a complex toxin derived therefrom. Forexample, the accumulation of viral coat proteins in transformed plantcells imparts resistance to viral infection and/or disease developmenteffected by the virus from which the coat protein gene is derived, aswell as by related viruses. See Beachy et al., Ann. Rev. Phytopathol.28:451 (1990). Coat protein-mediated resistance has been conferred upontransformed plants against alfalfa mosaic virus, cucumber mosaic virus,tobacco streak virus, potato virus X, potato virus Y. tobacco etchvirus, tobacco rattle virus and tobacco mosaic virus. Id.

(P) An insect-specific antibody or an immunotoxin derived therefrom.Thus, an antibody targeted to a critical metabolic function in theinsect gut would inactivate an affected enzyme, killing the insect. Cf.Taylor et al., Abstract #497, SEVENTH INT'L SYMPOSIUM ON MOLECULARPLANT-MICROBE INTERACTIONS (Edinburgh, Scotland, 1994) (enzymaticinactivation in transgenic tobacco via production of single-chainantibody fragments).

(Q) A virus-specific antibody. See, for example, Tavladoraki et al.,Nature 366:469 (1993), who show that transgenic plants expressingrecombinant antibody genes are protected from virus attack.

(R) A developmental-arrestive protein produced in nature by a pathogenor a parasite. Thus, fungal endo α-1,4-D-polygalacturonases facilitatefungal colonization and plant nutrient release by solubilizing plantcell wall homo-α-1,4-D-galacturonase. See Lamb et al., Bio/Technology10:1436 (1992). The cloning and characterization of a gene which encodesa bean endopolygalacturonase-inhibiting protein is described by Toubartet al., Plant J. 2:367 (1992).

(S) A developmental-arrestive protein produced in nature by a plant. Forexample, Logemann et al., Bio/Technology 10:305 (1992), have shown thattransgenic plants expressing the barley ribosome-inactivating gene havean increased resistance to fungal disease.

(T) Genes involved in the Systemic Acquired Resistance (SAR)

Response and/or the pathogenesis related genes. Briggs, S., CurrentBiology, 5(2) (1995).

(U) Antifungal genes (Cornelissen and Melchers, Pl. Physiol.101:709-712, (1993) and Parijs et al., Planta 183:258-264, (1991) andBushnell et al., Can. J. of Plant Path. 20(2):137-149 (1998).

2. Genes That Confer Resistance To A Herbicide, For Example:

(A) A herbicide that inhibits the growing point or meristem, such as animidazolinone or a sulfonylurea. Exemplary genes in this category codefor mutant ALS and AHAS enzyme as described, for example, by Lee et al.,EMBO J. 7: 1241 (1988), and Miki et al., Theor. Appl. Genet. 80:449(1990), respectively. See also, U.S. Pat. Nos. 5,605,011; 5,013,659;5,141,870; 5,767,361; 5,731,180; 5,304,732; 4,761,373; 5,331,107;5,928,937; and 5,378,824; and international publication WO 96/33270,which are incorporated herein by reference in their entireties for allpurposes.

(B) Glyphosate (resistance imparted by mutant5-enolpyruvl-3-phosphikimate synthase (EPSP) and aroA genes,respectively) and other phosphono compounds such as glufosinate(phosphinothricin acetyl transferase, PAT) and Streptomyceshygroscopicus phosphinothricin-acetyl transferase, bar, genes), andpyridinoxy or phenoxy propionic acids and cycloshexones (ACCaseinhibitor-encoding genes). See, for example, U.S. Pat. No. 4,940,835 toShah et al., which discloses the nucleotide sequence of a form of EPSPSwhich can confer glyphosate resistance. U.S. Pat. No. 5,627,061 to Barryet al. describes genes encoding EPSPS enzymes. See also U.S. Pat. Nos.6,248,876 B1; 6,040,497; 5,804,425; 5,633,435; 5,145,783; 4,971,908;5,312,910; 5,188,642; 4,940,835; 5,866,775; 6,225,114 B1; 6,130,366;5,310,667; 4,535,060; 4,769,061; 5,633,448; 5,510,471; Re. 36,449; RE37,287 E; and 5,491,288; and international publications WO 97/04103; WO97/04114; WO 00/66746; WO 01/66704; WO 00/66748 and WO 00/66747, whichare incorporated herein by reference in their entireties for allpurposes. Glyphosate resistance is also imparted to plants that expressa gene that encodes a glyphosate oxido-reductase enzyme as describedmore fully in U.S. Pat. Nos. 5,776,760 and 5,463,175, which areincorporated herein by reference in their entireties for all purposes.In addition glyphosate resistance can be imparted to plants by the overexpression of genes encoding glyphosate N-acetyltransferase. See, forexample, U.S. Application Ser. Nos. 60/244,385; 60/377,175 and60/377,719.

A DNA molecule encoding a mutant aroA gene can be obtained under ATCCAccession No. 39256, and the nucleotide sequence of the mutant gene isdisclosed in U.S. Pat. No. 4,769,061 to Comai. European PatentApplication No. 0 333 033 to Kumada et al. and U.S. Pat. No. 4,975,374to Goodman et al. disclose nucleotide sequences of glutamine synthetasegenes which confer resistance to herbicides such as L-phosphinothricin.The nucleotide sequence of a phosphinothricin-acetyl-transferase gene isprovided in European application No. 0 242 246 to Leemans et al. DeGreef et al., Bio/Technology 7:61 (1989), describe the production oftransgenic plants that express chimeric bar genes coding forphosphinothricin acetyl transferase activity. See also, U.S. Pat. Nos.5,969,213; 5,489,520; 5,550,318; 5,874,265; 5,919,675; 5,561,236;5,648,477; 5,646,024; 6,177,616 B1; and 5,879,903, which areincorporated herein by reference in their entireties for all purposes.Exemplary of genes conferring resistance to phenoxy propionic acids andcycloshexones, such as sethoxydim and haloxyfop, are the Acc1-S1,Acc1-S2 and Acc1-S3 genes described by Marshall et al., Theor. Appl.Genet 83:435 (1992).

(C) A herbicide that inhibits photosynthesis, such as a triazine (psbAand gs+ genes) and a benzonitrile (nitrilase gene). Przibilla et al.,Plant Cell 3:169 (1991), describe the transformation of Chlamydomonaswith plasmids encoding mutant psbA genes. Nucleotide sequences fornitrilase genes are disclosed in U.S. Pat. No. 4,810,648 to Stalker, andDNA molecules containing these genes are available under ATCC AccessionNos. 53435, 67441 and 67442. Cloning and expression of DNA coding for aglutathione S-transferase is described by Hayes et al., Biochem. J.285:173 (1992).

(D) Acetohydroxy acid synthase, which has been found to make plants thatexpress this enzyme resistant to multiple types of herbicides, has beenintroduced into a variety of plants (see, e.g., Hattori et al. (1995)Mol Gen Genet 246:419). Other genes that confer tolerance to herbicidesinclude: a gene encoding a chimeric protein of rat cytochrome P4507A1and yeast NADPH-cytochrome P450 oxidoreductase (Shiota et al. (1994)Plant Physiol 106:17), genes for glutathione reductase and superoxidedismutase (Aono et al. (1995) Plant Cell Physiol 36:1687, and genes forvarious phosphotransferases (Datta et al. (1992) Plant Mol Biol 20:619).

(E) Protoporphyrinogen oxidase (protox) is necessary for the productionof chlorophyll, which is necessary for all plant survival. The protoxenzyme serves as the target for a variety of herbicidal compounds. Theseherbicides also inhibit growth of all the different species of plantspresent, causing their total destruction. The development of plantscontaining altered protox activity which are resistant to theseherbicides are described in U.S. Pat. Nos. 6,288,306 B1; 6,282,837 B1;and 5,767,373; and international publication WO 01/12825, which areincorporated herein by reference in their entireties for all purposes.

3. Genes that Confer or Contribute to a Value-Added Trait, Such as:

(A) Modified fatty acid metabolism, for example, by transforming a plantwith an antisense gene of stearoyl-ACP desaturase to increase stearicacid content of the plant. See Knultzon et al., Proc. Nat'l. Acad. Sci.USA 89: 2624 (1992).

(B) Decreased phytate content

-   -   (1) Introduction of a phytase-encoding gene would enhance        breakdown of phytate, adding more free phosphate to the        transformed plant. For example, see Van Hartingsveldt et al.,        Gene 127:87 (1993), for a disclosure of the nucleotide sequence        of an Aspergillus niger phytase gene.    -   (2) A gene could be introduced that reduces phytate content. In        maize, this, for example, could be accomplished, by cloning and        then reintroducing DNA associated with the single allele which        is responsible for maize mutants characterized by low levels of        phytic acid. See Raboy et al., Maydica 35:383 (1990).

(C) Modified carbohydrate composition effected, for example, bytransforming plants with a gene coding for an enzyme that alters thebranching pattern of starch. See Shiroza et al., J. Bacteriol. 170:810(1988) (nucleotide sequence of Streptococcus mutans fructosyltransferasegene), Steinmetz et al., Mol. Gen. Genet. 200:220 (1985) (nucleotidesequence of Bacillus subtilis levansucrase gene), Pen et al.,Bio/Technology 10:292 (1992) (production of transgenic plants thatexpress Bacillus licheniformis α-amylase), Elliot et al., Plant Molec.Biol. 21:515 (1993) (nucleotide sequences of tomato invertase genes),Søgaard et al., J. Biol. Chem. 268:22480 (1993) (site-directedmutagenesis of barley α-amylase gene), and Fisher et al., Plant Physiol.102:1045 (1993) (maize endosperm starch branching enzyme 11).

(D) Elevated oleic acid via FAD-2 gene modification and/or decreasedlinolenic acid via FAD-3 gene modification (see U.S. Pat. Nos.6,063,947; 6,323,392; and WO 93/11245).

4. Genes that Control Male-Sterility

(A) Introduction of a deacetylase gene under, the control of atapetum-specific promoter and with the application of the chemicalN-Ac-PPT (WO 01/29237).

(B) Introduction of various stamen-specific promoters (WO 92/13956, WO92/13957).

(C) Introduction of the barnase and the barstar gene (Paul et al. PlantMol. Biol. 19:611-622, 1992).

Numerous methods for plant transformation have been developed, includingbiological and physical, plant transformation protocols. See, forexample, Miki et al., “Procedures for Introducing Foreign DNA intoPlants” in Methods in Plant Molecular Biology and Biotechnology, Glick,B. R. and Thompson, J. E. Eds. (CRC Press, Inc., Boca Raton, 1993) pages67-88. In addition, expression vectors and in vitro culture methods forplant cell or tissue transformation and regeneration of plants areavailable. See, for example, Gruber et al., “Vectors for PlantTransformation” in Methods in Plant Molecular Biology and Biotechnology,Glick, B. R. and Thompson, J. E. Eds. (CRC Press, Inc., Boca Raton,1993) pages 89-119. See also, U.S. Pat. No. 5,563,055, (Townsend andThomas), issued Oct. 8, 1996; U.S. Pat. No. 5,015,580 (Christou, et al),issued May 14, 1991; U.S. Pat. No. 5,322,783 (Tomes, et al.), issuedJun. 21, 1994. Two methods that can be utilized are Agromediatedtransformation and direct gene transfer. See U.S. Pat. No. 6,162,968,which is herein incorporated by reference.

INDUSTRIAL APPLICABILITY

The seed of soybean variety 91B42, the plant produced from the seed, thehybrid soybean plant produced from the crossing of the variety with anyother soybean plant, hybrid seed, and various parts of the hybridsoybean plant can be utilized for human food, livestock feed, and as araw material in industry.

The soybean is the world's leading source of vegetable oil and proteinmeal. The oil extracted from soybeans is used for cooking oil,margarine, and salad dressings. Soybean oil is composed of saturated,monounsaturated and polyunsaturated fatty acids. It has a typicalcomposition of 11% palmitic, 4% stearic, 25% oleic, 50% linoleic and 9%linolenic fatty acid content (“Economic Implications of Modified SoybeanTraits Summary Report”, Iowa Soybean Promotion Board & American SoybeanAssociation Special Report 92S, May 1990). Changes in fatty acidcomposition for improved oxidative stability and nutrition areconstantly sought after. Industrial uses of soybean oil which issubjected to further processing include ingredients for paints,plastics, fibers, detergents, cosmetics, and lubricants. Soybean oil maybe split, inter-esterified, sulfurized, epoxidized, polymerized,ethoxylated, or cleaved. Designing and producing soybean oil derivativeswith improved functionality, oliochemistry, is a rapidly growing field.The typical mixture of triglycerides is usually split and separated intopure fatty acids, which are then combined with petroleum-derivedalcohols or acids, nitrogen, sulfonates, chlorine, or with fattyalcohols derived from fats and oils.

Soybean is also used as a food source for both animals and humans.Soybean is widely used as a source of protein for animal feeds forpoultry, swine and cattle. During processing of whole soybeans, thefibrous hull is removed and the oil is extracted. The remaining soybeanmeal is a combination of carbohydrates and approximately 50% protein.

For human consumption soybean meal is made into soybean flour which isprocessed to protein concentrates used for meat extenders or specialtypet foods. Production of edible protein ingredients from soybean offersa healthy, less expensive replacement for animal protein in meats aswell as dairy-type products.

Genetic Marker Profile Through SSR

The present invention also comprises a soybean plant which may becharacterized by molecular and physiological data obtained from therepresentative sample of said variety deposited with the ATCC. Furtherprovided by the invention is a soybean plant formed by the combinationof the disclosed soybean plant or plant cell with another soybean plantor cell and characterized by being heterozygous for the molecular dataof the variety.

In addition to phenotypic observations, a plant can also be identifiedby its genotype. The genotype of a plant can be characterized through agenetic marker profile which can identify plants of the same variety ora related variety or be used to determine or validate a pedigree.Genetic marker profiles can be obtained by techniques such asRestriction Fragment Length Polymorphisms (RFLPs), Randomly AmplifiedPolymorphic DNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction(AP-PCR), DNA Amplification Fingerprinting (DAF), Sequence CharacterizedAmplified Regions (SCARs), Amplified Fragment Length Polymorphisms(AFLPs), Simple Sequence Repeats (SSRs) which are also referred to asMicrosatellites, and Single Nucleotide Polymorphisms (SNPs). Forexample, see Cregan, supra, which is incorporated by reference herein inits entirety.

Particular markers used for these purposes are not limited to anyparticular set of markers, but are envisioned to include any type ofmarker and marker profile which provides a means of distinguishingvarieties. One method of comparison is where only the loci for which91B42 is homozygous are used. For example, one set of publicly availablemarkers which could be used to screen and identify variety 91B42 isdisclosed in table A.

Soybean SSR Fingerprints with molecular size range alleles Allele SizeMarker 91B42 Satt572 172.2-174.2 Satt165 210.0-212.0 Satt042 163.1-165.1Satt300 253.7-255.7 Satt050 224.2-226.2 Satt385 149.0-152.0 Satt545290.3-292.3 Satt225 108.6-110.6 Satt133 163.3-165.3 Satt233 103.5-105.5Satt327 253.7-255.7 Satt421 144.6-148.6 Satt470 266.2-268.2 Satt455275.5-277.5 Satt409 186.7-188.7 Satt228 328.9-330.9 Satt426 204.9-206.9Satt509 192.0-194.0 Satt251 215.5-217.5 Satt197 192.6-194.6 Satt577312.0-314.0 Satt467 294.4-296.4 Sct034 130.1-132.1 Satt304 162.2-164.2Satt601 344.2-346.2 Satt556 148.1-150.1 Satt122 234.0-236.0 Satt534189.5-191.5 Satt565 302.6-304.6 Sct186 116.6-118.6 Satt227 326.6-328.6Satt432 257.7-259.7 Satt457 370.5-372.5 Satt557 219.8-221.8 Sct028235.8-237.8 Satt357 171.3-173.3 Satt532 172.6-174.6 Satt221 233.5-235.5Satt383 350.7-352.7 Satt295 222.8-224.8 Satt507 232.9-234.9 Satt147193.2-195.2 Satt266 330.4-332.4 Satt412 260.3-262.3 Satt546 356.9-358.9Satt172 167.0-169.0 Sctt008 158.7-160.7 Satt328 250.6-252.6 Satt372339.3-341.3 Satt582 335.8-337.8 Satt389 172.9-174.9 Satt543 198.0-200.0Satt186 366.9-368.9 Sct137 272.8-274.8 Satt213 325.6-327.6 Satt384153.1-155.1 Satt411 100.6-102.6 Satt598 162.8-164.8 Satt204 234.4-236.4Satt602 342.1-344.1 Satt452 259.1-261.1 Satt193 174.1-176.1 Satt348332.1-334.1 Sct188 251.7-253.7 Satt144 210.6-212.6 Sat090 349.5-351.5Satt594 147.0-149.0 Satt303 143.5-145.5 Satt517 161.9-163.9 Sat117209.8-211.8 Sct187 314.9-317.9 Satt353 159.0-161.0 Satt568 350.1-352.1Satt279 198.3-200.3 Satt142 143.8-145.8 Satt451 355.7-357.7 Satt367220.0-224.0 Satt127 244.0-246.0 Sctt012 351.5-353.5 Satt270 143.8-145.8Sat104 265.9-267.9 Satt440 306.9-308.9 Satt249 250.6-252.6 Satt596272.4-274.4 Satt380 150.7-152.7 Satt183 121.6-123.6 Satt431 347.6-349.6Satt102 159.6-161.6 Satt555 270.9-272.9 Satt441 176.1-178.1 Satt475149.9-151.9 Satt196 241.3-243.3 Satt523 170.8-172.8 Satt284 123.9-125.9Satt513 141.7-143.7 Satt590 338.1-340.1 Satt567 114.8-116.8 Satt540180.7-182.7 Satt175 168.8-170.8 Satt551 242.5-244.5 Satt250 188.5-190.5Satt336 181.7-183.7 Satt255 245.4-247.4 Satt234 177.9-179.9 Satt257254.9-256.9 Satt358 206.4-208.4 Satt259 207.9-209.9 Satt420 260.2-262.2Satt262 246.7-248.7 Satt478 253.8-255.8 Satt592 254.2-256.2 Satt153197.8-199.8 Satt243 333.7-335.7

Primers and PCR protocols for assaying these markers are disclosed onthe internet at 129.186.26.94/SSR.html. In addition to being used foridentification of Soybean variety, a soybean plant produced through theuse of 91B42, and the identification or verification of pedigree forprogeny plants produced through the use of 91B42, the genetic markerprofile is also useful in breeding and developing single geneconversions.

Means of performing genetic marker profiles using SSR polymorphisms arewell known in the art. SSRs are genetic markers based on polymorphismsin repeated nucleotide sequences, such as microsatellites. A markersystem based on SSRs can be highly informative in linkage analysisrelative to other marker systems in that multiple alleles may bepresent. Another advantage of this type of marker is that, through useof flanking primers, detection of SSRs can be achieved, for example, bythe polymerase chain reaction (PCR), thereby eliminating the need forlabor-intensive Southern hybridization. The PCR™ detection is done byuse of two oligonucleotide primers flanking the polymorphic segment ofrepetitive DNA. Repeated cycles of heat denaturation of the DNA followedby annealing of the primers to their complementary sequences at lowtemperatures, and extension of the annealed primers with DNA polymerase,comprise the major part of the methodology.

Following amplification, markers can be scored by gel electrophoresis ofthe amplification products. Scoring of marker genotype is based on thesize of the amplified fragment as measured by molecular weight (MW)rounded to the nearest integer. While variation in the primer used or inlaboratory procedures can affect the reported molecular weight, relativevalues should remain constant regardless of the specific primer orlaboratory used. When comparing varieties it is preferable if all SSRprofiles are performed in the same lab.

Primers used are publicly available and may be found in the Soybasesupra. or Cregan supra. See also, PCT Publication No. WO 99/31964Nucleotide Polymorphisms in Soybean, U.S. Pat. No. 6,162,967 PositionalCloning of Soybean Cyst Nematode Resistance Genes, and US 2002/0129402A1Soybean Sudden Death Syndrome Resistant Soybeans and Methods of Breedingand Identifying Resistant Plants, the disclosure of which areincorporated herein by reference.

The SSR profile of soybean plant 91B42 can be used to identify plantscomprising 91B42 as a parent, since such plants will comprise the samealleles as 91B42. Because the soybean plant is essentially homozygous atall relevant loci, an inbred should, in almost all cases, have only oneallele at each locus. In contrast, a genetic marker profile of an F1progeny should be the sum of those parents, e.g., if one inbred parenthad the allele 168 (base pairs) at a particular locus, and the otherinbred parent had 172 the hybrid is 168.172 (heterozygous) by inference.Subsequent generations of progeny produced by selection and breeding areexpected to be of genotype 168 (homozygous), 172 (homozygous), or168.172 for that locus position. When the F1 plant is used to produce aninbred, the locus should be either 168 or 172 for that position.

In addition, plants and plant parts substantially benefiting from theuse of 91B42 in their development such as 91B42 comprising a single geneconversion, transgene, or genetic sterility factor, may be identified byhaving a molecular marker profile with a high percent identity to 91B42.Such a percent identity might be 98%, 99%, 99.5% or 99.9% identical to91B42.

The SSR profile of 91B42 also can be used to identify essentiallyderived varieties and other progeny varieties developed from the use of91B42, as well as cells and other plant parts thereof. Progeny plantsand plant parts produced using 91B42 may be identified by having amolecular marker profile of at least 25%, 30%, 35%, 40%, 45%, 50%, 55%,60%, 65%, 70%, 75%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 99.5% geneticcontribution from soybean variety. Such plants may be developed usingthe markers identified in WO 00/31964, U.S. Pat. No. 6,162,967 andUS2002/0129402A1.

Unique SSR Profiles

While determining the SSR genetic marker profile of the plants describedsupra, several unique SSR profiles may be identified which did notappear in either parent of such plant.

Such unique SSR profiles may arise during the breeding process fromrecombination or mutation. A combination of several unique allelesprovides a means of uniquely identifying a plant variety, a hybridproduced from such variety, and progeny produced from such variety andcomprising such unique SSR profile, regardless of the number ofgenerations or breeding cycles removed. Such progeny may be furthercharacterized as being within a pedigree distance of 91B42, such aswithin 1,2,3,4 or 5 or less cross-pollinations to a soybean plant otherthan 91B42 or a plant that has 91B42 as a progenitor. Unique molecularprofiles may be identified with other molecular tools such as SNPs andRFLPs.

Unique Marker Profile Analysis

TABLE B Table B gives Unique Marker Profile data for soybean variety91B42. TRAIT LINKAGE GROUP plasmid 91B42 SCN Lg G p10355B-1 R SCN Lg B1p12198A-1 R SCN Lg G p7659A-2 R SCN Lg B1 p8584A-1 R RPS6 Lg G p10792A-1RPS6 R = Resistant marker S = Susceptible marker SON resistance basedupon information disclosed in US 6,162,967 A Phytophthora resistancebased upon information in public sector for linkage groups N, F, and GSCN resistance, based upon information in US 6,271,437 B1Protocals used in determining resistance follow:Phytophthora Root Rot Growth Chamber Screening

i Phytophthora root rot (PMG) screens are conducted in growth room (GR).The plants are inoculated when the unifoliate leaves are present, butnot yet expanded. Four days after inoculation, the plants are removedfrom the chamber for evaluation and scoring. A 9-point scoring system ofevaluating the number of live plants over total inoculated is used. Forexample: a score of “9” indicates that 9 out of 9 plants are alive andgrowing; a score of “5” indicates that 5 of the nine plants survivedinoculation; a score of “1” would imply that none of the plants lived.

The differentials used, and the genes that it corresponds with are asfollows:

Gene (Rps) Differential 1a L75-6141 1b L77-1863 1c L75-3735 1d PI1030911k WM82 3a L83-570 3b L91-8347 3c 31937N172 4 L85-2352 5 L85-3059 6 62XX7 L93-3458 susc. Sloan

Soybean Cyst Nematode Scoring

The traditional method for classifying SCN resistance in soybeanvarieties has been the Index of Parasitism (IP). The amount of SCNreproduction on a variety is compared to that of a susceptiblebenchmark, usually Lee or Lee74, to determine the IP for that variety.This procedure assigns SCN resistance into four discrete classes: ≦10%IP are considered resistant (R); 11-30% IP are considered moderatelyresistant (MR); 31-60% IP are considered moderately susceptible (MS);and >61% IP are considered susceptible (S). This standard has been usedalmost universally by both public and private soybean breeders for thepast 30 years.

Index of Variety Score Parasitism 9  0-7% IP 8  8-15% 7 16-23% 6 24-32%5 33-40% 4 41-50% 3 51-60% 2 61-70% 1 >71%

Iron deficiency chlorosis screening nurseries are planted in May onsoils (in the field) known to induce yellowing symptoms in soybean. Thevarieties are usually scored in early July, the exact date is dependentupon the progression of the symptoms. The rating scale below is used.

Iron Chlorosis Scores

Score Symptoms 9 All plants are normal green color. 8 A few plants areshowing very light chlorosis on 1 or 2 leaves. 7 Less than half of theplants showing moderate chlorosis (light green leaves). 6 More than halfthe plants showing moderate chlorosis, but no necrosis seen on leaves. 5Most plants are light green to yellow, no necrosis seen on leaves. Mostplants are stunted (50-75% of normal height). 4 Most plants are yellow,necrosis seen on edges of less than half the leaves. Most plants areapp. 50% of normal height. 3 Most plants are yellow, necrosis seen onmost leaves. Most plants are app. 20-40% of normal height. 2 Most leavesare almost dead, most stems are still green. Plants are severely stunted(10-20% of normal height) 1 Most plants are completely dead. The plantsthat are still alive are app. 10% of normal height, and have very littleliving tissue.

The foregoing were used to determine resistance as reported herein.

Performance Examples of 91B42

In the examples that follow in Table 2, the traits and characteristicsof soybean variety 91B42 are given in paired comparisons with the fivePioneer varieties 9132, 91B53, 9163, 9172, and 91B92. These results show91B42 and the comparison variety grown in the same replication(s), witheach replication being conducted in the same growing conditions and thesame year. Table 2 shows mean values for the stated number ofreplications of 91B42 and the paired comparison variety. The datacollected on each soybean variety is presented for key characteristicsand traits, with one characteristic or trait shown per Table 2 section.For example, with respect to yield bu/a shown in the first section ofTable 2, there were 42 replications comparing the yield of 91B42 to theyield of 9132. 91B42 had a mean value of 48.0 bushels per acre for these42 replications. Thus, 91B42 yielded 2.2 bu/a more than 9132, which isstatistically significant (P=0.01). In addition to a significantlyhigher yield when compared to 9132, 91B42 showed significantly betterscores for tolerance to iron-deficiency chlorosis. In the comparison of91B42 to 91B53, 91B42 had significantly earlier maturity. The datacomparing 91B42 to 9163 showed that 91B42 had significantly higheryield, significantly fewer lodged plants, and significantly greaterscores for tolerance to iron-deficiency chlorosis. When 91B42 wascompared to 9172, 91B42 had significantly greater scores for toleranceto iron-deficiency chlorosis. In the comparison of soybean variety 91B42to 91B92, 91B42 demonstrated significantly better seedling vigor scoresand significantly greater scores for tolerance to iron-deficiencychlorosis.

TABLE 2 1476 VARIETY COMPARISON DATA FOR 91B42 YIELD YIELD YIELD YIELDYIELD bu/a bu/a bu/a bu/a bu/a Mean 2 Reps Diff 91B42 Mean 2 Prob 9132 22.2 8.0 5.8 0.01 91B53 37 −2.4 7.4 9.8 0.01 9163 42 2.4 8.0 5.6 0.009172 29 −0.1 9.8 9.8 0.95 91B92 12 −2.3 4.0 6.3 0.20 MAT MAT MAT MAT MATABS ABS ABS ABS ABS Mean 2 Reps Diff 91B42 Mean 2 Prob 9132 25 3.2 127.1124.0 0.00 91B53 23 −2.6 126.9 129.5 0.00 9163 25 −1.4 127.1 128.5 0.009172 19 −2.1 127.8 129.9 0.00 91B92 6 −4.5 124.8 129.3 0.01 HGT HGT HGTHGT HGT Mean 2 Reps Diff 91B42 Mean 2 Prob 9132 12 0.6 34.3 34.9 0.2891B53 11 0.0 34.2 34.2 1.00 9163 12 4.3 34.3 38.7 0.00 9172 8 0.4 37.638.0 0.58 91B92 4 1.0 27.8 28.8 0.42 LDGSEV LDGSEV LDGSEV LDGSEV LDGSEVMean 2 Reps Diff 91B42 Mean 2 Prob 9132 7 0.4 6.1 5.7 0.59 91B53 5 1.06.4 7.4 0.14 9163 7 1.7 6.1 4.4 0.04 9172 7 0.1 6.1 6.3 0.85 91B92 . . .. . EMGSC EMGSC EMGSC EMGSC EMGSC Mean 2 Reps Diff 91B42 Mean 2 Prob9132 17 −0.7 5.1 5.8 0.39 91B53 17 −0.4 5.1 5.5 0.62 9163 17 −2.2 5.17.4 0.00 9172 11 −2.3 4.8 7.1 0.04 91B92 6 −1.5 5.7 7.2 0.19 SDVIG SDVIGSDVIG SDVIG SDVIG Mean 2 Reps Diff 91B42 Mean 2 Prob 9132 16 0.6 7.1 6.40.26 91B53 16 0.7 7.1 6.4 0.28 9163 16 −0.7 7.1 7.8 0.16 9172 10 −1.46.6 8.0 0.04 91B92 6 0.8 7.8 7.0 0.04 HYPL HYPL HYPL HYPL HYPL Mean 2Reps Diff 91B42 Mean 2 Prob 9132 9 −1.4 6.6 8.0 0.14 91B53 9 3.4 6.6 3.20.10 9163 9 −2.4 6.6 8.9 0.04 9172 6 −0.9 8.1 9.0 0.08 91B92 3 0.3 3.53.1 0.19 FEC FEC FEC FEC FEC Mean 2 Reps Diff 91842 Mean 2 Prob 9132 51.8 6.3 4.6 0.00 91B53 2 0.5 6.3 5.8 0.20 9163 25 0.7 6.3 5.6 0.02 917219 1.6 5.8 .3 0.00 91B92 6 2.8 7.8 5.0 0.01

DEPOSITS

Applicants have made a deposit of at least 2500 seeds of Soybean Variety91B42 with the American Type Culture Collection (ATCC), Manassas, Va.20110 USA, ATCC Deposit No. PTA-4649. The seeds deposited with the ATCCon Sep. 6, 2002 were taken from the deposit maintained by PioneerHi-Bred International, Inc., 800 Capital Square, 400 Locust Street, DesMoines, Iowa 50309-2340 since prior to the filing date of thisapplication. Access to this deposit will be available during thependency of the application to the Commissioner of Patents andTrademarks and persons determined by the Commissioner to be entitledthereto upon request. Upon allowance of any claims in the application,the Applicant(s) will make available to the public, pursuant to 37C.F.R. § 1.808, samples of the deposit of at least 2500 seeds of variety91B42 with the American Type Culture Collection (ATCC), 10801 UniversityBoulevard, Manassas, Va. 20110-2209. This deposit of the Soybean Variety91B42 will be maintained in the ATCC depository, which is a publicdepository, for a period of 30 years, or 5 years after the most recentrequest, or for the enforceable life of the patent, whichever is longer,and will be replaced if it becomes nonviable during that period.Additionally, Applicants have satisfied all the requirements of 37C.F.R. §§1.801-1.809, including providing an indication of the viabilityof the sample upon deposit. Applicants have no authority to waive anyrestrictions imposed by law on the transfer of biological material orits transportation in commerce. Applicants do not waive any infringementof their rights granted under this patent or under the Plant VarietyProtection Act (7 USC 2321 et seq.). U.S. Plant Variety Protection ofSoybean Variety 91B42 has been applied for under Application No.200200079.

All publications, patents and patent applications mentioned in thespecification are indicative of the level of those skilled in the art towhich this invention pertains. All such publications, patents and patentapplications are incorporated by reference herein to the same extent asif each was specifically and individually indicated to be incorporatedby reference herein.

The foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding.However, it will be obvious that certain changes and modifications suchas single gene modifications and mutations, somoclonal variants, variantindividuals selected from large populations of the plants of the instantvariety and the like may be practiced within the scope of the invention,as limited only by the scope of the appended claims.

1. A method for producing a soybean variety with resistance to race 3 ofSoybean Cyst Nematode and multi-race Phytophthora resistance comprisingcrossing soybean variety 91B42, a sample of said soybean varietydeposited under ATCC Accession Number PTA-4649, with a second soybeanplant to yield progeny soybean seed, wherein soybean plants grown fromsaid seed comprise said resistance.
 2. The method of claim 1 furthercomprising growing said progeny soybean seed to yield a 91B42-derivedsoybean plant.
 3. Progeny soybean seed produced by the method ofclaim
 1. 4. A soybean plant produced by growing the seed of claim
 3. 5.The soybean plant of claim 4, wherein the plant further comprisesresistance to iron deficiency chlorosis.
 6. The soybean plant of claim4, said plant comprising an allele for RPS1k resistance, an allele forRPS6 resistance and at least one allele for Soybean Cyst Nematoderesistance.
 7. The soybean plant of claim 4, wherein said plantcomprises the following marker loci: p7659A-2 on linkage group Lg G,p8584A-1 on linkage group Lg B1, p10355B-1 on linkage group Lg G,p12198A-1 on linkage groups Lg B1 and multi-race Phytophthora resistanceas determined by a loci selected from the group consisting of p10792A-1on linkage groups Lg G, and p13069A-1 on linkage group Lg N.